Combination beam shift-grid control tube



Jan. 4, 1949. THQMA 2,457,949

COMBINATION BEAM SHIFT-GRIDCONTROL TUBE Original Filed Aug. 14, 1943 INVENTOR.

Patented Jan. 4, 1949 COMBINATION BEAM SHIFT-GRID CONTROL TUBE Albert G. Thomas, Lynchburg, Va.

Original application August 14, 1943, Serial No. 498,621. Divided and this application May 31, 1945, Serial No. 596,906

Claims. (01. 250-275) This invention relates to electronic tubes and is a division from my co-pending application, Serial No. 498,621, filed August 14, 1943.

In electronic ground speed indicators of the type described in the above application, and in numerous electronic circuits it is desirable to control a grid type tube by means of a shifted beam tube. An object therefore is to provide a combination tube in which charges on a grid are varied according to the position, magnitude, or alignment of a beam or stream of electrons.

Another object is to provide a double chamber tube, one chamber enclosing means for forming a stream of electrons and the other chamber enclosing at least a cathode, anode, and a grid which can be charged by means of the electron stream in the other chamber. a

A further object is to provide a combination tube of the general type described, either tube of which can be used independently of the other if desired.

Another object is to provide a timing device comprising a tube with an electron stream oscillated or shifted at predetermined frequency so that the grid of an associated gaseous relay tube will be charged to fire the relay after a predetermined number of oscillations of the stream.

A further object is to provide an electronic relay that will fire after a predetermined change of frequency applied to a component of the relay.

An additional object is to provide an electronic tube or combination tube that can be used in a ground speed indicator for aircraft.

Other objects will appear in the specification.

Figure l is a part. sectional elevation of my combination tube, showing a connected oscillator.

Figure 2 is a top sectional view of the tube made by a plane passing above the grids and below the anodes.

In the drawing, envelope l contains cathode 2 which is photoemissive, and of rectangular shape if desired. Anode 3 may be similarly shaped and ring 4 may be used to decelerate or to focus the electron stream 5 which may have considerable width as indicated.

Conductor l, of metal, graphite, or equivalent material, is fastened to the envelope and is sealed in position so that electron stream 5 normally does not strike it. Conductor I is connected with grid 8 which has lead Ill sealed in envelope 9 which may be separate or sealed to envelope l as shown. Anode H and cathode l2, which may be photoemissive or thermionic as indicated, are also pro vided in envelope 9.

In operation, if this device is arranged with the anodes connected to the positive terminal of asuitable potential source or sources and if the cathodes are connected to the negative terminal or terminals; the ring 4 being also properly connected and grid 8 being connected to cathode or ground through a suitable grid leak preferably, then electron stream 5 will be defiected tostrike element 1 when the device is moved through the earths magnetic field on an aircraft. It is assumed of course that the device will be properly aligned. The degree of bending of stream 5 will be in proportion to the ground speed of the carrying aircraft so that as the speed increases element 1 will intercept a greater proportion of the electron stream. Grid 81 will therefore become negatively charged to a degree dependent upon the ground speed of the aircraft and the current passing between cathode l2 and anode II will be varied in accordance with the aircraft ground speed. This current can be passed through an electrical instrument I'I calibrated in miles per hour ground speed.

The combination tube shown, in which a deflected electron stream or beam strikes and charges a grid controlling another circuit, has wide uses other than for ground speed indicators. For instance, envelope I may be highly evacuated and envelope 9 may contain gas such as argon or the like so that this part of the tube, including anode H, grid 8, and cathode l2, functions as an electronic relay. Beam 5 can then be defiected away from element 1 by charges on plates 13 and M to bring grid 8 to a positive or less negative potential sufiicient to fire the gaseous relay.

A suitable grid leak It may be connected with grid 8 so that negative charges on the grid will leakofi at a rate dependent upon the value of the grid leak and upon the potential of the grid. Ifthen beam 5 is causedto oscillate by alternating charges on plates [3 and I4, at definite frequency say, by means of connected crystalcontrolled or other oscillator l5, then electrons will be supplied to grid 8 at a rate dependent upon the frequency of oscillation or deflection of the beam and this rate can be varied to keep grid 8 negatively charged to prevent the gaseous tube from firing or to allow the electrons to leak off faster than they are supplied to the grid so that the relay tube will fire after a predetermined lowering of frequency.

Since frequency can be controlled relatively accurately, by crystals or otherwise, this can be made to be a very accurate electronic relay which will conduct after a given number of deflections negative potential of the grid 8 will be sufiiciently' 1 reduced to allow the relay to conduct.

Elements l3 and M or element 4 could of course be used as grids to vary the stream from cathode 2 quantitatively. I

Element 1 may be placed at any optimum position intermediate cathode 2 and anode 3 or between cathode l2 and anode H, and anode 3 may be of any suitable shape or dimension to collect all or a part of the electron stream 5. A suitable condenser can be connected between grid 8 and cathode 12 if desired, to increase the time required for the electrons to leak off.

While I have shown a specific embodiment it is apparent that numerous changes of detail can be made without departing from the broad'p-rinciples I have disclosed.

What I claim is:

1. An electronic tube comprising, a first cathode, a first anode positioned to receive electrons from said first cathode, a second cathode spaced from said first cathode, a second anode positioned to receive electrons from said second cathode, grid means positioned intermediate said cathodes and said anodes for controlling electron flow between said first cathode and said first anode, and means intermediate said second cathode and said second anode for producing a field to shift the stream of electrons travelling from said second-cathode to said second anode relative to said grid means to vary the potential thereof.

2. In an electronic tube having two separate adjacent chambers; a first cathode, a first anode,

and control means therebetween, in one said chamber; a second cathode, and a second anode in the other said chamber, a portion of said control means passing through a wall of said tube and situated intermediate said second cathode and said second anode, and means intermediate said second cathode and said second anode for producing a field to shift the stream of electrons travelling from said second cathode to said second anode with respect to said control means portion to vary the potential of said control means.

3. An electronic tube comprising, means iorming a first chamber and a second chamber; a first cathode, a first anode, and grid means therebetween in said first chamber; a second cathode,

and a second anode in said second chamber; a portion of said grid means passing through a wall of said tube and situated intermediate said second cathode and said second anode; means intermediate said second cathode and said second anode for producing a field to shift electrons passing from said second cathode to said second anode relative to said grid means portion to vary the potential of said grid means, and means intermediate said second cathode and said second anode for reducing the speed of electrons passing therebetween.

4, An electronic tube comprising, a first cathode, a first anode positioned to receive electrons from said first cathode, a second cathode spaced from said first cathode, a second anode positioned to receive electrons from said second cathode, grid means positioned intermediate said cathodes and said anodes for controlling electron fiow between said first cathode and said first anode, and means intermediate said second cathode and said second anode for producing a field to shift the stream of electrons travelling between said second cathode and said second anode at predetermined frequency relative to said grid means to vary the potential thereof.

5. An electronic tube comprising, a first cathode, a first anode positioned to receive electrons from said first cathode, a second cathode spaced from said first cathode, a second anode positioned to receive electrons from said second cathode, grid means positioned intermediate said cathodes and said anodes for controlling electron flow between said first cathode and said first anode, said grid means being also positioned to intercept a'portion of the electrons from said second cathode, and means intermediate said second cathode and said second anode for producing a field to reduce the speed of electrons emitted from said second cathode.

- ALBERT G. THOMAS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

